package Traverse.traverse2018;


import domain.TreeNode;

public class PreOrderTraverse {

    public static void main(String[] args) {
        TreeNode node1 = new TreeNode(1);
        TreeNode node2 = new TreeNode(2);
        TreeNode node3 = new TreeNode(3);
        TreeNode node4 = new TreeNode(4);
        TreeNode node5 = new TreeNode(5);
        TreeNode node6 = new TreeNode(6);
        TreeNode node7 = new TreeNode(7);
        node1.left = node2;
        node1.right = node3;
        node2.left = node4;
        node2.right = node5;
        node3.left = node6;
        node3.right = node7;
        node4.left = node4.right = null;
        node5.left = node4.right = null;
        node6.left = node4.right = null;
        node7.left = node4.right = null;
        preOrderTraverse(node1);
    }

    public static void preOrderTraverse(TreeNode root) {
        if (root == null) {
            return;
        }
        System.out.println(root.val);
        preOrderTraverse(root.left);
        preOrderTraverse(root.right);
    }

}
